Summary of the Invention
The present invention relates to a system for providing wireless communication between various items located in a factory. More specifically, the system provides both the function of tracking the location of items equipped with microterminals and also provides the function of providing direct communication between microterminals and between a central controller and microterminal.
The apparatus of the present invention is particularly suitable for use in semiconductor manufacturing facilities. In such facilities, wafer carriers and work-in-progress (WIP) boxes are used to transport semiconductor wafers from one work location to another. Each wafer carrier in the factory is typically paired with the WIP box which is designed to contain the wafer carrier and its contents to prevent contamination of the semiconductor wafers. In one embodiment, the apparatus includes a microterminal attached to the WIP box and a microterminal attached to the wafer carrier. In other embodiments, a microterminal is attached to either the wafer carrier or the WIP box and an identification tag is attached to the other of the WIP box or the carrier. The identification tag could be in the form, for example, of a bar code label or in the form of an electronic tag. In either event, the microterminal must be equipped in such a way that it can "read" the data of the tag. In any of these embodiments, there is communication of identification information to at least one microterminal for purposes of establishing and verifying that the proper wafer carrier is located within the proper WIP box.
In addition to the basic elements of the system outlined above, the system may also include a plurality of transceivers mounted strategically throughout the factory. The transceivers are hardwired to a system controller. The transceivers can then be used to communicate information between the system controller and the microterminals in the factory. The system is also designed so that the microterminals and transceivers can be used to track the location of microterminals within the factory. One system similar to the present invention is described in U.S. Pat. No. 5,742,238, which is hereby incorporated by reference. While the system described there is very suitable for tracking the location of microterminals in the factory and for providing two-way communication between the microterminals and central controller via the transceivers, that application does not disclose the exchange of identification information between microterminals and/or tags attached to a pair of containers, such as a WIP box and a wafer carrier, that are intended to work in tandem. The primary advantage contemplated by the subject invention here is to prevent misprocessing of the wafers because of inadvertent mixing of WIP boxes and wafer carriers.
A greater understanding of the present invention and its many advantages can be derived from a review of the following detailed description of the invention, the drawings contained herein, and the claims set forth below.